Volume backscattering strengths have been measured close in space and time to midwater trawls in which small deep-sea fishes were caught. The acoustic experimental method was to deploy both an omnidirectional and a directional hydrophone and to detonate small explosive charges. The experiments were all conducted at nighttime, and were repeated both inside and outside a warm-core eddy. The trawling net, which had a cross-sectional area of 8 m2, was towed at speeds of 2 to 3 kn and at depths between 30 and 360 m. The results have been analyzed at frequencies from 2.5 to 20 kHz, although the net did not capture any fish large enough to resonate at frequencies below 4 kHz. Trawls at some depths yielded few fish, and the scattering strengths at these depths increased at around 12 dB/oct. This scattering may have been due to zooplankton that were too small to be retained by the mesh. At depths where large numbers of fish were caught, there was reasonable agreement between the measured and predicted scattering strengths at frequencies greater than 5 kHz.